Bobbin clutch for spindles



Allg 25, 1931. G. H. MAGRATH 1,820,574

BOBBIN CLUTCH FOR SPINDLES Filed July 25, 1928 Patented Aug. 25, 1931 elicited: HQMAG'RATH. or WHITINSVI'LLE', MASSACHUSETTS A 'Bolsena'V CLUTCH Foa SPINDLES i Application filed-July .25, 1928.1 serial No. 295,158.

Thefobjects of thepresent invention4 are to providek a bobbin clutch whichis simple and economical to' manufacture and. assemble,which iseificien't and durablein use,;andA

ywhich is generallyv superiorto previousibobbin clutches of the same various novel features of construction and functional advantages of this invention will n be evident from, the' following description;

-andappended claims. For the purposes of illustration one concrete embodiment of the invention is shown in the accompanyingdrawings, inwhlch.V

Fig. 1 is a side elevation; c Fig.k 2 is a section on-line 2 2 of Fig.-1; VFig. 3 is a Section on line 3.#3 ofFig.2; .Figg 4 is a development of theI spring hereinafter described; and Y l A ,l

Fig. 5 is a side View of one ofthe contact pieces lactuated by the spring. 'y

The particular embodiment yf the invention chosen for the purpose of illustration comprises an ordinary blade 1 anda whirl 2 ixedly mounted on kthe blade ,byV a pressed fit, thewhirl 2 havingy ahub l3 fromwhich,` projects a neck4 and aange 5 VwithV an` Awhichis preferably taperedy at the inner end, as shown in Fig. l3. Mounted on kthe blade inopposition tothe hub Bis-fa case (Shaving four radial slots extending longitudinallyy from one end throughout the maj or portion of the length of the ycase leaving therebetween ingerportions 7 cess between the neck 4 annular recess therebetween,

and the c flange 5.

Disposed in theaforesaid slots arel contactl piecesv 8 having their outer ends hooked vtoj 6, as shown in, F ig. 3,l

engage insidel the 'case and having their-inner ends disposed with- 40 in the annular recess between the neck 4 and,

the flange 5. i

Mounted in thek aforesaidannular recess is a` springhaving a circular-base 9 and projecting fingers 10,. the base-9 lying between-the neck- 4` and the inner endsof'the ngers? and contact pieces v8. This Spring,

indicated generally bythe lettervSjis preferably formed from a sheet metal blanky (Fig. 4) whichv isvbenty into Vcircular form.

The normaljnterior diameter of the spring general type. The V whichproject intothe rebase 9 may-be somewhat less than the external diameter of the neck 4 so that the springr will yieldinglygrip the neck or the spring may be shaped so thatthe normal exterior diameter of the base 9 isslightly greaterl vthan the internal diameter of the case 64 so that when the spring isy inserted in `thefcasev itexpands outwardly against the inner ends of the lingers 7. The springprojections or ngerslO flare outwardly toward their `free k yends-,and engage the :contactf'pieces 8 near their hooked ends, as shown in Fig.` 3. The width ofthe spring projections 10 is preferably equal tod or somewhatxless `than the f widthzof the contact pieces 8; andthe oppog5 I .site side of` eachcontact piece 8 andeach slot in .case .6 lare 4parellel to each .other yas shown in :Fig. 2. T he'combined radial thicknessr of the spring 9y and the case fin-kV gers v-7 is approximately-equalto the *widthgqcif of the annular recess between neck 4 and flange 5` so that-'when the case 6 is forced vinto the recess Vthe taper ofthe 'recess com;l

presses the fingers 7 againstgthe spring9 tightly clamping. the case and Spring in the recess. The thickness; of the inner ends of. the contact pieces 8 is somewhatless than the thickness ofthe fingers 7 sov that the contactpieces fit Vloosely in the upper'portion of the yrecess butl do tit snugly the reduced lower end of the recesssothat these contactl pieces l' have substantially fixed fulcrum points at their` extreme lower ends, where these ends seat inthe bottom ofthe recess,A as shownlin Fig. ,3; j Y In-additionto the aforesaid pressed fit of-the case jand spring S inthe annulary recessof the hub?) the lcase 6 may also have a pressed it directly with the blade 1 at its outerwend, :thereby more firmly securing the caseinrxed position` on the blade. lIn as-y semblingthe parts the whirlv 2 ispreferably vapplied tothe blade 1 rst; and the springl may then be applied eitherto the neck `4,- in Iwhich case the internal diameter ofv theV spring base `9 ispreferably lessthan the ,exfv ternal diameter of the neck. 4, so thatthe Springfclingsto the neck, or to the case 6 with the spring fingers 10 projecting into the slots in thecase, in-,which case the yexn n ternal diameter of the spring base is preferably larger than the internal diameter of the case so that the spring clings to the case. After the spring has been applied to the neck or case as aforesaid the case is forced into said annular recess while the contact pieces 8 are held in position on the case also to enter the annular recess.

In operation the spring projections 10 press outwardly on the contact pieces 8 holding the outer hooked ends against the case 6 and the inner ends against the fiange 5. When a bobbin is applied over the blade l and thence over the case 6 until it abuts against the fiange 5 the contact pieces are pressed inwardly against the spring action, whereupon the spring fingers l() yieldingly engage the bobbin through the medium of the contact pieces 8 detachably to hold the bobbin in position.

From the foregoing it will bev evident that the spring is held in position by interengagement of the case and the whirl so that the spring need not be applied by a separate pressed-fit operation and it may be made in the form of a split ring from sheet metal without welding or brazing, thereby materially reducing the cost of manufacture and labor of assemblage. l

Another important feature of the invention consists in the arrangement whereby the spring extends into the whirl thereby aflording greater length of spring fingers without necessarily increasing the length of the case 6. If the spring were fitted to the blade l (instead of the neck 4) in end to end relation to the neck 4, one or the other of two difficulties would be encountered, viz., the spring fingers would be too short and stubby to be efficient or the case 6 and contact pieces 8 would have to be elongated beyond the standard optimum dimensions. f

I claim:

1. Apparatus of the character described comprising a blade, a whirl mounted on the blade, the whirl having a hub provided with a neck fitting around the blade and an annular recess surrounding the neck, a case' mounted on the blade and having spaced fingers extending into said recess, bobbin contact members disposed in the spaces between said fingers and extending into said recess, and a spring having a base secured in said recess between said neck and the inner ends of the fingers and contact members, the spring having projections extending from its base at spaced intervals and bearing against said contact members, the thickness of the inner ends of the contact members being less than the thickness of the fingers so that the contact members fit loose` 1y in said recess. n

2. Apparatus of the character described comprising a blade, a whirl mounted on the blade, the whirl having a hub provided with a neck fitting around the blade and an annular recess surrounding the neck, a case mounted on the blade and having spaced fingers extending into said recess, bobbin contact members disposed in the spaces between said fingers and extending into said recess, and a spring having a base secured in said recess between said neck and the inner ends of the fingers and contact members, the spring having projections extending from its base at spaced intervals and bearing against said contact members, the thickness of the inner ends of the contact members being less than the thickness of the lingers so that the Contact members fit loosely in said recess, and-said spring projections fiaring outwardly at their outer ends thereby to urge the contact members outwardly with respect to the case fingers.

3. rApparatus of the character described comprising a blade, whirl and casing members mounted thereon and having opposed recesses therein, one of these members having its recess annular in form and spaced Vfrom the blade, ngers on the other of these members and extending into the annular recess, a spring comprising a base portion disposed in the annular recess in firm engagement with a plurality of the fingers and with the inner wall of the recess for locking such fingers and the spring from relative circumferential movement, the spring having a least one resilient arm extending from the spring base longitudinally and outwardly of the blade in a slot formed by adjacent fingers, a contact segment disposed longitudinally of' the blade and within said slot, the free ends of this segment being disposed within and retained by the opposed recesses of the Whirl andcasing members, the spring arm being in engagement with this segment at a point intermediate the ends of the latter and remote from the base of the spring, and means providing a substantially fixed fulcrum point for that end of the contact segment which is disposed in the annular recess.

4. Apparatus of the character described comprising a blade, whirl and casing members mounted thereon and having opposed I.'

recesses therein, one of these members having its recess annular in form and spaced from the blade, fingers on the other of these members and extending into the annular recess and in firm engagement with the outer wall thereof, a spring comprising a substantially annular base portion disposed within the annular recess in firm engagement with a plurality of the fingers and with the inner wall of this recess for locking such fingers and the spring fromrelative circum-y ferential movement, the annular base of the spring having a normal diameter slightly different from its diameter when assembled so that this base portion may yieldably engage and be retained on one of the members which it engages when assembled for facilitating assembly, circumferentially spaced spring arms on the base of the spring and extending longitudinally and outwardly of In the blade in slots formed by adjacent fingers for engagement with contact segments, a contact segment disposed longitudinally of the blade and within each of these` slots, the free ends of each segment being dis- 10 posed Within and retained by the opposed recesses of the whirl and casing members, I the spring arms being in engagement with the respective segments at points intermediate the ends thereof and remote from the base of the spring, and means 4providing substantially fixed fulcrum points for those ends of the contact segments which are disposed in the annular recess adjacent the base of the spring. j

5. Apparatus of the character described comprising a blade, Whirl and casing members mounted thereon and having opposed recesses therein, one of these members having its recess annular in form and spaced from theV blade, this annular recess increasing in diameter from the base toward the open side thereof so that its outer wall is inclined to provide -clearance for movement of contact segments, lingers on the otherof these members and extending into the annular recess in firm engagement with the inclined outer wall thereof, a spring comprising a substantially annular base portion 35 disposed within the annular recess in firm engagement with a plurality of the fingers 'and with the inner wall of this recess for locking such fingers and the spring from relative circumferential movement, circumferentially spaced spring arms on the base of the spring and extending longitudinally and outwardlyv of the blade in slots formed by adjacent fingers for engagement with contact segments, a contact segment disposed longitudinally of the blade and within each of these slots, the free ends of each segment being disposed within and retained by the opposed recesses of the `whirl and casing members, the spring arms being in engage- 50 ment with the respective segments at points intermediate theends thereof and remote from the base of thek spring so that these arms may be relatively long and flexible, the ends of the contact segments which are disposed in the annular recess being substantially in abutment with the base of the` latter and fitting snugly between the inclined outer wall of this krecess and the base of the spring, whereby the contact segments 63 may rock about these ends as substantially fixed fulcrum points.

Signed byme at Whitinsville, Massachusetts this 21st day of July, 1928.

GEORGE H. MAGRATH. 

